Publications Details

Two-channel wakeup system employing aluminum nitride based MEMS resonant accelerometers for near-zero power applications

Reger, Robert W.; Yen, Sean Y.; Barney, Bryson B.; Satches, Michael R.; Young, Andrew I.; Pluym, Tammy P.; Wiwi, Michael W.; Delaney, Matthew A.; Griffin, Benjamin G.

The Defense Advanced Research Project Agency has identified a need for low-standby-power systems which react to physical environmental signals in the form of an electrical wakeup signal. To address this need, we design piezoelectric aluminum nitride based microelectromechanical resonant accelerometers that couple with a near-zero power, complementary metal-oxide-semiconductor application specific integrated circuit. The piezoelectric accelerometer operates near resonance to form a passive mechanical filter of the vibration spectrum that targets a specific frequency signature. Resonant vibration sensitivities as large as 490 V/g (in air) are obtained at frequencies as low as 43 Hz. The integrated circuit operates in the subthreshold regime employing current starvation to minimize power consumption. Two accelerometers are coupled with the circuit to form the wakeup system which requires only 5.25 nW before wakeup and 6.75 nW after wakeup. The system is shown to wake up to a generator signal and reject confusers in the form of other vehicles and background noise.